复数： obstructors

To obstructor delay the progress of .

阻碍或耽搁……的过程。

Analysis on the internal obstructor to library development .

图书馆发展过程中的内部阻滞因素分析。

Repair of half maxillary bone defect applying magnetic attachment and non root obstructor .

应用磁性附着体及无顶式阻塞器修复半侧上颌骨缺损。